The transmission electron microscope for observing an object to be inspected, with applying the electron beams therein, being radiated from an electron gun and penetrating through a specimen, is already known in various kinds of documents, including the following Patent Documents 1 and 2, and so on, for example, and it is widely applied in an observation of nano-metric structure of a thin specimen, etc. Namely, it is a method of observing the structure inside that specimen, by means of the transmission electron microscope; i.e., while irradiating the electron beams upon the specimen, the electron beams penetrating the specimen is projected, enlargedly, on a screen or/and a 2D detector, and there can be obtained a projection image that is reflecting absorption of the electron beams inside the specimen object thereon.